LITTLE ROCK — A former Arkansas judge on Thursday challenged a ballot measure that would cap damages awarded in lawsuits and would give the Legislature control over court rules in the state.

Former Pulaski County Circuit Judge Marion Humphrey filed a lawsuit challenging a proposed constitutional amendment that the state Legislature voted to put on the November ballot. The measure limits damages that can be awarded in civil lawsuits and the contingency fees attorneys can receive in those suits. The measure also would give the Legislature power to change, repeal or adopt rules for the state’s courts.

Humphrey’s lawsuit claims the measure tries to unconstitutionally combine four separate and disparate proposals, and says it violates the separation of powers between the judicial and legislative branches. He’s asking a Pulaski County judge to disqualify the measure and prevent election officials from counting any votes for it.

“(The proposal) attempts to claw back what the Arkansas Legislature has previously admitted and recognized as the Arkansas Supreme Court’s vested constitutional, inherent and statutory authority,” the lawsuit said.

The proposed amendment caps noneconomic damages awarded in lawsuits to $500,000 and would restrict punitive damages to $500,000 or three times the amount of compensatory damages awarded, whichever is higher. The Legislature would be able to increase these limits with a two-thirds vote of the House and Senate. It also caps attorneys’ contingency fees at 33 1/3 percent of the net amount recovered in the suit.

A spokesman for Secretary of State Mark Martin, who’s named as the defendant in the suit, did not have a comment on the filing.

The measure has the backing of business groups such as the state Chamber of Commerce that have argued the limits are needed to make Arkansas more competitive with surrounding states. The majority-Republican Legislature voted last year to refer the measure to voters.

“It is now time to let the voters decide the issue,” said Carl Vogelpohl, campaign manager with Arkansans for Jobs and Justice, the group campaigning for the measure. “Once again, trial lawyers are attempting to use the court to protect their own pocketbooks by seeking to deny Arkansas voters a voice.”

Opponents have said the amendment would supersede juries by placing an arbitrary limit on damages, an argument Humphrey echoed in his lawsuit.

“This proposal would close the doors to the courthouse for ordinary citizens and effectively extinguish their right to a jury trial in all cases,” the lawsuit said.